Transport at Nanoscale Interfaces Laboratory

Electric field tunable bandgap in twisted double trilayer graphene

Perrin, M. L., Jayaraj, A., Ghawri, B., Watanabe, K., Taniguchi, T., Passerone, D., Calame M. & Zhang, J.

npj 2D Materials and Applications, 8. (2024)

https://doi.org/10.1038/s41699-024-00449-w

 

Abstract
Twisted van der Waals heterostructures have recently emerged as a versatile platform for engineering interaction-driven, topological phenomena with a high degree of control and tunability. Since the initial discovery of correlated phases in twisted bilayer graphene, a wide range of moiré materials have emerged with fascinating electronic properties. While the field of twistronics has rapidly evolved and now includes a range of multi-layered systems, moiré systems comprised of double trilayer graphene remain elusive. Here, we report electrical transport measurements combined with tight-binding calculations in twisted double trilayer graphene (TDTLG). We demonstrate that small-angle TDTLG (~1.7−2.0∘) exhibits an intrinsic bandgap at the charge neutrality point. Moreover, by tuning the displacement field, we observe a continuous insulator-semimetal-insulator transition at the CNP, which is also captured by tight-binding calculations. These results establish TDTLG systems as a highly tunable platform for further exploration of magneto-transport and optoelectronic properties.